The present invention may relate to a release coating comprising a mixture of silicon nitride and silicon powder. In certain embodiments, the release coating may inhibit or prevent the formation of a silicon carbide (SiC) alloy that can act as a bond or adhering agent between a silicon part and a graphite part.
Graphite has many properties that may make it a useful material on which to grow silicon parts. But in some instances, silicon can bond to the graphite, forming a SiC alloy.
The semiconductor industry may use quartz crucibles to line graphite parts. In some instances, this works well, such as where the interface between the quartz and the silicon may be discarded. Where silicon parts need to be released—for example, in ingot casting or other wafer casting processes—mixtures of Si3N4 or SiO2 may be used as release coatings. See U.S. Pat. No. 4,218,418.